The present invention comprises a new and distinct cultivar of calla lily, botanically known as Zantedeschia sprengeri and hereinafter referred to by the cultivar name ‘Aspen’.
‘Aspen’ is a product of a planned breeding program which had the objective of creating Zantedeschia hybrids for cut inflorescence production in a wide range of colors with a large, classic inflorescence shape. The breeding program began in 1989 and the new cultivar is a seedling selected from the crossing of Zantedeschia sprengeri seedling Z030479 (female parent, unpatented) with Zantedeschia sprengeri variety ‘Chrystal Blush’ (male parent, unpatented). ‘Aspen’ was selected in 2008 by the inventor C. J. J. Randag in 't Zand, The Netherlands as one flowering plant within the progeny of the stated cross.
The first act of asexual reproduction of ‘Aspen’ by tissue culture was performed by the inventor in August of 2008 in 't Zand, The Netherlands. Further asexual reproductions by tissue culture at the same location has demonstrated that the combination of characteristics as herein disclosed for the new cultivar are retained and reproduced true to type through successive generations of asexual reproduction.
The following observations, measurements and comparisons describe plants grown in 't Zand, The Netherlands under greenhouse conditions which approximate those generally used in horticultural practice. Color references are made to The R.H.S. Colour Chart of The Royal Horticultural Society of London, except where general color terms of ordinary significance are used.
The present invention has not been evaluated under all possible environmental conditions. The phenotype may vary with variation in environment without a change in the genotype of the plant.
The following traits have been repeatedly observed and determined to basic characteristics of ‘Apen’ which, in combination, distinguish this calla lily as a new and distinct cultivar:                1. Pure white-colored spathe;        2. Fast forcing time; and        3. High inflorescence production.        
Table 1 provides similarities and differences of ‘Aspen’ to its parents and ‘Captain Ventura’ (U.S. Plant Pat. No. 21,245).
TABLE 1‘Aspen’SimilaritiesDifferencesZ030479Leaf shapeNumber of spathes‘Chrystal Blush’Leaf shapeSpots on leavesVery small and late pink blush‘Captain Ventura’Leaf shapeSpathe colorSpathe shape